System and method for automated brew cycles

Abstract

A system includes: a water reservoir configured to store water; a brew chamber extending below and contiguous with the water reservoir; a piston configured to run in the brew chamber, defining a base of the water reservoir, defining a port extending between the water reservoir and the brew chamber, and including a valve coupled to the fill port and operable in a) a closed position during downward advancement of the piston and b) an open position during upward retraction of the piston; a heating element configured to heat water occupying the brew assembly; and an actuator configured to retract the piston to transfer water from the water reservoir, through piston via the port, and into the brew chamber and to advance the piston by a target piston travel distance—corresponding to a piston swept volume that yields a target brew volume—to displace liquid from the brew chamber.

We claim: 
     
       1. A system comprising:
 a base defining a scale receptacle; 
 a scale configured to transiently locate in the scale receptacle and to output a weight signal; and 
 a rocker arm; 
 a column supporting the rocker arm above the base; 
 a brew assembly:
 supported on the column between the base and the rocker arm; and 
 comprising:
 a water reservoir configured to store a first volume of water; 
 a brew chamber extending below and contiguous with the water reservoir; 
 a set of mating features arranged below the brew chamber opposite the water reservoir; and 
 a portafilter configured to transiently couple to the set of mating features; 
 
 
 a piston:
 configured to run in the brew chamber; 
 coupled to the rocker arm; 
 defining a fill port extending between the water reservoir and the brew chamber; and 
 comprising a valve coupled to the fill port and operable in:
 a closed position during downward advancement of the piston within the brew chamber; and 
 an open position during upward retraction of the piston within the brew chamber; 
 
 
 an actuator:
 arranged in the column; and 
 coupled to the rocker arm; 
 
 a heating element:
 arranged in the brew assembly; and 
 configured to heat the first volume of water occupying the brew assembly; 
 
 a temperature sensor configured to output a temperature signal representing a temperature of the first volume of water occupying the brew assembly; and 
 a controller configured to:
 activate the heating element; 
 in response to the temperature of the first volume of water reaching a target temperature, trigger the actuator to retract the piston to transfer water from the water reservoir through the fill port and into the brew chamber; and 
 trigger the actuator to advance the piston to displace liquid from the brew chamber and through the portafilter toward the base; 
 access the weight signal from the scale seated in the scale receptacle while the actuator advances the piston to displace liquid from the brew chamber; 
 calculate a dispense volume of liquid from the portafilter based on the weight signal; and 
 trigger the actuator to cease advancement of the piston in response to the dispense volume reaching a target brew volume. 
 
 
     
     
       2. The system of  claim 1 :
 wherein the rocker arm comprises:
 a pivot mounted to the column; 
 a first end coupled to the actuator; and 
 a second end coupled to the piston via a connecting rod; and 
 
 wherein the controller is configured to:
 access a target brew pressure; 
 track a pressure in the brew chamber based on:
 a force output of the actuator; 
 a cross-sectional area of the piston; and 
 distances between the pivot, the first end, and the second end of the rocker arm; and 
 
 modulate a speed of the actuator while advancing the piston to maintain the target brew pressure within the brew chamber and displace liquid from the brew chamber. 
 
 
     
     
       3. The system of  claim 1 , wherein the valve comprises a straight-through check-valve:
 arranged in the piston and fluidly coupled to the fill port; 
 configured to transition into the closed position in response to an increase in pressure in the brew chamber during downward advancement of the piston; and 
 configured to transition into the open position in response to a decrease in pressure in the brew chamber during upward retraction of the piston. 
 
     
     
       4. The system of  claim 1 :
 wherein the scale receptacle comprises a charge receptacle; 
 wherein the scale comprises a charge port configured to engage the charge receptacle in response to insertion onto the scale receptacle; and 
 further comprising:
 a wireless communication module coupled to the controller and configured to wirelessly receive the weight signal from the scale; and 
 a display:
 arranged on the column; 
 configured to render a brew parameter during the brew cycle; and 
 configured to render a weight value received from the scale in response to removal of the scale from the scale receptacle. 
 
 
 
     
     
       5. The system of  claim 1 :
 wherein the water reservoir is configured to store a maximum water volume less than twice a maximum swept volume of the piston between the purge position and a maximum retracted position in the brew chamber; and 
 wherein the controller is configured to, following placement of a vessel under the portafilter:
 trigger the actuator to retract the piston to the maximum retracted position to transfer remaining water in the water reservoir into the brew chamber; and 
 trigger the actuator to advance the piston to the purge position:
 to displace remaining liquid from the brew chamber, through the portafilter, and into the second vessel; and 
 to compress and dry coffee grounds occupying the portafilter. 
 
 
 
     
     
       6. The system of  claim 1 :
 wherein the temperature sensor:
 is arranged in the piston proximal an upper surface of the piston; and 
 is configured to output the temperature signal representing the temperature of the first volume of water occupying the water reservoir; 
 
 further comprising a lower temperature sensor:
 is arranged in the piston proximal a lower surface of the piston; and 
 configured to output a second temperature signal representing a temperature of liquid occupying the brew chamber; and 
 
 wherein the controller is configured to:
 access a target bloom temperature; 
 activate the heating element to heat the volume of water occupying the water reservoir; 
 in response to the temperature of the first volume of water approaching the target temperature, trigger the actuator to retract the piston upwardly to draw water from the water reservoir into the brew chamber; 
 during a bloom period, selectively activate the heating element to maintain liquid occupying the brew chamber proximal the target bloom temperature based on the second temperature signal; and 
 in response to completion of the bloom period, trigger the actuator to advance the piston downwardly to displace liquid from the brew chamber. 
 
 
     
     
       7. The system of  claim 1 :
 wherein the piston further comprises a pressure port facing the brew chamber; 
 further comprising a pressure sensor:
 arranged in the piston; 
 fluidly coupled to the pressure port; and 
 configured to output a pressure signal representing a pressure within the brew chamber between the piston and the portafilter; and 
 
 wherein the controller is configured to, during a brew cycle:
 access a target brew pressure; 
 trigger the actuator to advance the piston downwardly toward the portafilter at an initial speed; 
 detect a first pressure in the brew chamber at a first time based on the pressure signal received from the pressure sensor; 
 in response to the first pressure exceeding the target brew pressure, reduce the initial speed to a first speed; 
 detect a second pressure in the brew chamber at a second time based on the pressure signal received from the pressure sensor; and 
 in response to the second pressure falling below the target brew pressure, increasing the first speed to a second speed. 
 
 
     
     
       8. The system of  claim 1 , further comprising a screen:
 arranged in the brew chamber adjacent and above the portafilter; and 
 configured to:
 prevent water from flowing from the brew chamber into the portafilter when pressure within the brew chamber remains below a threshold pressure and prior to downward advancement of the piston; and 
 distribute water, loaded between the piston and screen, across coffee grounds occupying the portafilter in response to pressure within the brew chamber exceeding the threshold pressure during downward advancement of the piston. 
 
 
     
     
       9. The system of  claim 1 , wherein the controller is configured to, during a brew cycle:
 trigger the actuator to retract the piston upwardly to draw water from the water reservoir, through the valve, and into the brew chamber; 
 trigger the actuator to advance the piston downwardly toward the portafilter at a first speed and over a first time duration to drive coffee grounds into pores defined by the portafilter; and 
 trigger the actuator to advance the piston downwardly toward the portafilter at a second speed and over a second time duration to dispense liquid from brew chamber through the portafilter:
 the second time duration greater than the first time duration; and 
 the second speed less than first speed. 
 
 
     
     
       10. The system of  claim 1 :
 further comprising a pressure sensor configured to output a pressure signal representing a pressure within the brew chamber between the piston and the portafilter; and 
 wherein the controller is configured to, during a brew cycle:
 access a target piston travel distance corresponding to a piston swept volume approximating a target brew volume; 
 trigger the actuator to advance the piston downwardly toward the portafilter; 
 based on the pressure signal received from the pressure sensor:
 detect a first pressure in the brew chamber when the piston occupies a first piston position at a first time; and 
 detect a second pressure in the brew chamber when the piston occupies a second piston position, below the first piston position, at a second time succeeding the first time; and 
 
 in response a pressure difference between the first pressure and the second pressure exceeding a threshold pressure difference:
 detect saturation of coffee grounds occupying the portafilter at the second time; and 
 trigger the actuator to advance the piston downwardly to a third position, offset below the second position by the target piston travel distance, to dispense the target brew volume of liquid from the portafilter. 
 
 
 
     
     
       11. A system comprising:
 a base; 
 a brew assembly:
 supported over the base; and 
 comprising:
 a water reservoir configured to store a first volume of water; 
 a brew chamber extending below and contiguous with the water reservoir; 
 a set of mating features arranged below the brew chamber opposite the water reservoir; and 
 a portafilter configured to transiently couple to the set of mating features; 
 
 
 a piston:
 configured to run in the brew chamber; 
 defining a fill port extending between the water reservoir and the brew chamber; and 
 comprising a valve coupled to the fill port and operable in:
 a closed position during downward advancement of the piston within the brew chamber; and 
 an open position during upward retraction of the piston within the brew chamber; 
 
 
 an actuator:
 coupled to the piston; 
 
 a heating element:
 arranged in the brew assembly; and 
 configured to heat the first volume of water occupying the brew assembly; 
 
 an upper temperature sensor:
 arranged in the piston proximal an upper surface of the piston; and 
 configured to output a first temperature signal representing a temperature of the first volume of water occupying the water reservoir; 
 
 a lower temperature sensor:
 arranged in the piston proximal a lower surface of the piston; and 
 configured to output a second temperature signal representing a temperature of liquid occupying the brew chamber; and 
 
 a controller configured to:
 access a target bloom temperature; 
 activate the heating element to heat the volume of water occupying the water reservoir; 
 in response to the first temperature of the first volume of water approaching the target bloom temperature, trigger the actuator to retract the piston upwardly to draw water from the water reservoir through the fill port and into the brew chamber; and 
 during a bloom period, selectively activate the heating element to maintain liquid occupying the brew chamber proximal the target bloom temperature based on the second temperature signal; and 
 in response to completion of the bloom period, trigger the actuator to advance the piston downwardly to displace liquid from the brew chamber and through the portafilter. 
 
 
     
     
       12. The system of  claim 11 , wherein the controller is configured to:
 access a target piston travel distance corresponding to a piston swept volume yielding a target brew volume; 
 trigger the actuator to retract the piston by the target piston travel distance to transfer water from the water reservoir through the fill port and into the brew chamber; and 
 trigger the actuator to advance the piston by the target piston travel distance to dispense the target brew volume of liquid from the portafilter. 
 
     
     
       13. The system of  claim 12 :
 further comprising a user interface:
 arranged on the column and configured to receive the target brew volume; and 
 
 wherein the controller is configured to:
 retrieve a nominal water saturation volume of coffee grounds occupying the portafilter; 
 calculate the piston swept volume based on a sum of the target brew volume and the nominal water saturation volume; and 
 transform the piston swept volume into the target piston travel based on a cross-sectional area of the piston. 
 
 
     
     
       14. The system of  claim 11 :
 wherein the base defines a scale receptacle; 
 further comprising a scale configured to transiently seat in the scale receptacle and to output a weight signal; and 
 wherein the controller is configured to, during a brew cycle:
 access the weight signal from the scale seated in the scale receptacle while the actuator advances the piston to displace liquid from the brew chamber; 
 calculate a dispense volume of liquid from the portafilter based on the weight signal; and 
 trigger the actuator to cease advancement of the piston in response to the dispense volume reaching a target brew volume. 
 
 
     
     
       15. The system of  claim 14 , wherein the controller is configured to:
 detect placement of a first vessel under the portafilter in response to a first change in the weight signal received from the scale; 
 following detection of placement of the first vessel under the portafilter:
 trigger the actuator to advance the piston to a dispense position to displace liquid from the brew chamber, through the portafilter, and into the first vessel; 
 
 detect removal of the first vessel in response to a second change in the weight signal received from the scale; and 
 following detection of placement of a second vessel under the portafilter:
 trigger the actuator to advance the piston from the dispense position to a purge position to displace remaining liquid from the brew chamber, through the portafilter, and into the second vessel. 
 
 
     
     
       16. A system comprising:
 a base; 
 a brew assembly:
 supported over the base; and 
 comprising:
 a water reservoir configured to store a first volume of water; 
 a brew chamber extending below and contiguous with the water reservoir; 
 a set of mating features arranged below the brew chamber opposite the water reservoir; and 
 a portafilter configured to transiently couple to the set of mating features; 
 
 
 a piston:
 configured to run in the brew chamber; 
 defining a fill port extending between the water reservoir and the brew chamber; and 
 comprises a pressure port facing the brew chamber; 
 comprising a valve coupled to the fill port and operable in:
 a closed position during downward advancement of the piston within the brew chamber; and 
 an open position during upward retraction of the piston within the brew chamber; 
 
 
 an actuator:
 arranged in the column; and 
 coupled to the rocker arm; 
 
 a heating element:
 arranged in the brew assembly; and 
 configured to heat the first volume of water occupying the brew assembly; 
 
 a temperature sensor configured to output a temperature signal representing a temperature of the first volume of water occupying the brew assembly; 
 a pressure sensor:
 arranged in the piston; 
 fluidly coupled to the pressure port; and 
 configured to output a pressure signal representing a pressure within the brew chamber between the piston and the portafilter; and 
 
 a controller configured to:
 access a target brew pressure; 
 activate the heating element; 
 in response to the temperature of the first volume of water reaching a target temperature, trigger the actuator to retract the piston, at an initial speed, to transfer water from the water reservoir through the fill port and into the brew chamber; and 
 detect a first pressure in the brew chamber at a first time based on the pressure signal received from the pressure sensor; 
 in response to the first pressure exceeding the target brew pressure, reduce the initial speed to a first speed; 
 detect a second pressure in the brew chamber at a second time based on the pressure signal received from the pressure sensor; and 
 in response to the second pressure falling below the target brew pressure, increase the first speed to a second speed; and 
 trigger the actuator to advance the piston to displace liquid from the brew chamber and through the portafilter toward the base.